Outrigger stabilizer for cranes



Aug. 13, 1968 0.1.. CRISP 3,396,854

OUTRIGGER STABILIZER FOR CRANES Filed June 19, 1967 'll 8 ./v/////// I 486 52 FIG. 5

INVENTOR. ORIS L. CRISP BY a, (70? ATTORNEY United States Patent 3,396,854 OUTRIGGER STABILIZER FOR CRANES Oris L. Crisp, Box 637, Heppner, Oreg. 97836 Filed June 19, 1967, Ser. No. 647,009 8 Claims. (Cl. 212145) ABSTRACT OF THE DISCLOSURE An outrigger stabilizer for cranes comprises a beam arranged for extension and retraction. A stabilizer leg with attached foot is pivoted to the end of the beam. Rack and pinion means raise and lower the leg and foot with retraction and extension of the beam.

This invention relates to an outrigger assembly for stabilizing cranes, derricks, hoists and other load-lifting apparatus.

Although it is commonplace to fit cranes and similar apparatus with stabilizing feet, the stabilizing arrangements of the prior art have been relatively cumbersome, awkward, ineflicient, and inapplicable in certain locations of the crane. In addition, it frequently is necessary manually to attach them on the job site and then manually to remove them before moving the crane to another location.

It is the general purpose of the present invention to provide an outrigger stabilizer for cranes and like apparatus which overcomes the above objections in that it is simple in its construction, efiicient in its operation, applicable universally to various types of cranes and adjustable without disassembly between a raised, inoperative position and a lowered, ground-engaging position.

In addition the outrigger stabilizer of my invention is braced when in use, rapid in its adjustment between raised and lowered positions, usable singly or in pairs, positioned high above the axle of the crane where it will not bury in mud or banks, and shiftable to an inoperative position in which it is out of the way when traveling.

The manner in which the foregoing and other objects of this invention are accomplished will be apparent from the specification and claims considered together with the accompanying drawings, wherein:

FIG. 1 is a fragmentary view of a crane in front elevation, partly in section; showing the manner of mounting the outrigger stabilizer of my invention;

FIG. 2 is a detailed fragmentary view in side elevation illustrating the construction of one of the outrigger stabilizing units;

FIG. 3 is a transverse sectional view taken along line 33 of FIG. 2;

FIG. 4 is a longitudinal sectional view taken in a horizontal plane along line 44 of FIG. 2;

FIG. 5 is a longitudinal view taken in a vertical plane along line 55 of FIG. 3; and

FIG. 6 is a fragmentary, detail view in elevation of a stabilizing foot and leg assembly in an alternate form.

Generally stated, the outrigger stabilizer of my invention comprises a rack fixed to the crane and extending outwardly therefrom. A guideway is arranged parallel and adjacent to the rack and houses a support beam. Drive means are connected to the beam for reciprocating it between the extended and retracted positions.

Pivot means pivotally connects the inner end of the stabilizing leg to the outer end of the beam. A foot is connected to the outer end of the leg. Pinion gear means are fixed to the inner end of the leg in engagement with the rack. They are operative to shift the leg angularly between a raised, inoperative position and a lowered groundengaging position with retraction and extension of the beam respectively.

3,396,854 Patented Aug. 13, 1968 ice Thus there is mounted at all times on the crane an integral stabilizing assembly which may be shifted to an inoperative position when the crane is traveling, but which rapidly may be lowered to a ground-engaging, operative position when the work site is reached.

Considering the foregoing in greater detail and with particular reference to the drawings:

As shown in FIG. 1, the outrigger stabilizer of my invention may be used in conjunction with a crane or related apparatus having a body 10 mounted on "a frame or chassis 12. The crane is mounted on wheels 13 and accordingly is mobile so that it may be moved from place to place.

The crane is provided in selected locations, for example at the front and back, on both sides, with independently operated outrigger stabilizing units.

To this end there is provided a guideway 14 in which slideably is mounted a beam 16. The forward end of the beam is provided with an outwardly projecting clevis 18.

Drive means are provided for reciprocating beam 16 between retracted and extended positions.

In the illustrated form of the invention the drive means comprises a fluid operated cylinder, preferably an hydraulic cylinder 20. On the rear end of the case of the cylinder is a tab 22 which pivotally is secured to the frame by means of a pivot pin 24.

The piston rod 26 of the cylinder has a head 28 which pivotally is connected to spaced standards 30 on beam 16 by means of pivot pin 32. Thus reciprocation of piston rod 26 of the cylinder extends and retracts beam 16.

Mounted on the outer end of beam 16 are a stabilizer leg 34 and a stabilizer foot 36.

To mount stabilizer leg 34, the outer end of beam 16 is provided with a forwardly-projecting, transversely perforated ear 38. Ear 38 is received between the component members of clevis 18 and is held in place by a rotatable shaft 40.

Stabilizer leg 24 preferably comprises a double acting hydraulic cylinder 34, the piston 42 of which forms a connection for foot 36. However, an alternate leg construction may be employed is desired.

As shown in FIG. 6 the alternate leg may comprise a cylinder 34a having an adjustment opening 44. The con necting shaft 42a of foot 36 is provided with longitudinally spaced transverse openings 46. The openings through shaft 42a and cylinder 34a may be placed in registration with each other at the desired degree of extension of foot 36 and pin 48 inserted through the registering openings, thus releasably locking the foot in its desired position of extension.

Means also are provided for moving leg 34 angularly between raised and lowered positions contemporaneously with the retraction and extension of beam 16. This is accomplished by rack and pinion means illustrated particularly in FIGS. 2 and 4.

Fixed to the underside of transverse frame member 12 is a stout, reinforced plate 50. The upper surface 52 of the plate is downwardly tapered in the outward direction.

Plate 50 mounts a pair of spaced racks 54 having transverse teeth 56.

Rotatable shaft 40, which is coupled to beam 16, has fixed to each of its ends a pinion gear 60. The teeth of these gears mesh with the teeth of racks 54.

In the preferred form of the invention, pinion gears 60 are segmental and eccentric in radius. As evident particularly in FIG. 2, r which is the radius of the working segment of the gear in the operative position of leg 34 and foot 36, is substantially greater than the dimension r which is the radius of that segment of the gear which works when the leg and foot are in their elevated or retracted position.

This arrangement has two advantages.

First, it gives more lifting power at the beginning of the stroke, where it is most needed. Second, it shortens the stroke by as much as one-half, thereby making it possible to build the unit more compactly.

Stop means are provided for limiting the oscillating movement of leg 34 at the extremes of its travel path. At the upper extremity of its travel path it abuts against a beam guide and stop bar 62 suitably mounted on the front end of structural member 12. At the lower end of its travel path it abuts against an arcuate stop 64 formed integrally with plate 50 in the leading end thereof.

As is evident particularly in FIG. 4, when the leg nests within this arcuate stop it is braced in three directions. The unit thus is strong in its operational position.

To operate the unit, cylinder 20 is extended to retract beam 16 from its FIG. 1 position. During its retraction pinion gears 60 engage racks 54.

Continuing movement of beam 16 toward its retracted position thereupon will swing stabilizing legs 34 and feet 36 upwardly in the direction indicated by the arrow of FIG. 2. This angular motion will continue until the legs abut against stop pad 52.

The crane then may be moved to another location and the above sequence reversed. Cylinder 20 is retracted, extending beam 16. Engagement of pinion gears 58 with racks 54 will lower the leg-foot assembly to the full line position of FIG. 2, where it is fully braced by arcuate stop 54. Extension of cylinder 34 then will place foot 36 firmly in contact with the ground, with the upper surface of beam 16 bearing against beam guide and stop bar 62. In the alternative, foot 36 may be adjusted relative to leg 34a by placing pin 48 in the appropriate one of registering openings 44.

Any one or all of the units may thus be employed, depending upon the terrain in which the crane is to be used.

Thus it will be seen by the present invention I have provided an outrigger stabilizer for cranes which is simple in construction, secure in use and versatile in its application under all of the commonly encountered conditions of operation.

It is to be understood that the form of my invention herein shown and described is to be taken as an illustrative example of the same and that various changes in the shape, size and arrangement of parts may be resorted to without departing from the spirit of my invention or the scope of the subjoined claims.

Having thus described my invention, I claim:

1. An outrigger stabilizer for cranes comprising:

(a) rack means fixed to the crane and extending outwardly therefrom,

(b) a support beam,

(c) a guideway arranged parallel and adjacent to the rack and housing the beam,

(d) drive means connected to the beam for reciprocating it between retracted and extended positions,

(e) a stabilizing leg,

(f) pivot means pivotally connecting the inner end of the leg to the outer end of the beam,

(g) a foot connected to the outer end of the leg,

(h) and pinion gear means fixed to the inner end of the leg meshing with the rack and operative to shift the leg with attached foot angularly between a raised, inoperative position and a lowered ground-engaging position with retraction and extension of the beam respectively.

2. The outrigger stabilizer of claim 1 wherein the drive means for the beam comprises fluid operated cylinder means.

3. The outrigger stabilizer of claim 1 wherein the stabilizing leg comprises a telescoping stabilizing leg of 'adjustable length.

4. The outrigger stabilizer of claim 1 wherein the stabilizing leg comprises a telescoping stabilizing leg of adjustable length and including lock pin means for releasably locking the telescoping leg in selected positions of extension.

5. The outrigger stabilizer of claim 1 wherein the stabilizing leg comprises a telescoping stabilizing leg of adjustable length, the leg mounting a fluid operated cylinder having a reciprocating piston rod, and means for mounting the foot on the end of the piston rod.

6. The outrigger stabilizer of claim 1 wherein the pinion gear mean-s is of eccentric radius, the radius increasing as the leg moves to its operative position, and wherein the rack means is tapered to accommodate the eccentric radius of the pinion gear means.

7. The outrigger stabilizer of claim 1 and including brace means bracing the leg in its lowered, ground engaging position.

8. The outrigger stabilizer of claim 1 wherein the rack means comprises a pair of parallel racks positioned one on each side of the stabilizing leg and interconnected by a plate, wherein the pinion gear means comprise a pair of pinion gears arranged one on each side of the stabilizing leg and engaging the racks, and wherein the connecting plate connecting the racks is provided with an arcuate cutaway portion dimensioned to receive the stabilizing leg in bearing, bracing relationship.

References Cited UNITED. STATES PATENTS 2,131,479 9/1938 McGiffert 2l2-l45 2,777,586 1/1957 Boysen 212- 3,167,188 1/1965 Burgess 2l2l45 RICHARD E. AEGERTER, Primary Examiner.

H. C. HORNSBY, Assistant Examiner. 

